1. Field of the Invention
The present invention relates to a toner container used in image-forming apparatuses such as copying machine or printers, and also relates to a sealing film for sealing an opening of such toner containers.
2. Related Background Art
Powder containers for storing a toner powder comprised of a formed container member and a lid material film are widely employed, as the structure of the opening can be manufactured in a simple manner, and moreover, an even greater degree of sealing can be achieved.
This sort of container is widely used particularly for toner containers for supplying a toner, as the lid material film can be peeled away after the container has been set in the apparatus such as a copying machine, thereby facilitating prevention of soiling due to scattered toner.
The method for removing the lid material film of such a toner container after the container has been set in the apparatus such as a copying machine, involves extending one end of the lid material film from a slit provided near a door of the copying machine, etc., for inserting and removing the toner container therefrom, thus allowing for the lid material film to be removed by means of extracting the edge of the lid material film. A common configuration employed in such an arrangement is to provide a portion of the lid material film, which is longer than the length of the container, and which is folded back over the aforementioned container.
Another method widely employed for such toner powder containers is in view of the toner capacity and other factors to seal the opening of the toner powder container and thereby seal the toner within, and then peel away part of the lid material film when opening a supplying orifice, which is smaller than the aforementioned container opening. An advantage of this method is that the opening in the lid material film can be maintained at a constant, regardless of the size of the toner container of the capacity thereof.
In such an arrangement, a supplying orifice must be opened in the lid material film so as to be smaller than the container opening and to be at a set position. For example, in Japanese Patent Application Laid-Open No. 59-13262 there is disclosed an example of lid material film for a toner container which has such an opening. The lid material film is comprised of a lid material film which is approximately the same size as the formed opening of the toner container, and a lid material film formed along a supplying opening which is smaller than the formed opening of the toner container, the later smaller lid material film is laid upon the former. Thus an opening is formed along the lid material film upon peeling-away, thereby enabling an opening to be obtained in a constant manner.
Further, in U.S. Pat. No. 4,931,838, there is disclosed a processing cartridge wherein an opening is formed between the toner cartridge and the developer by means of pulling tear-tape which is applied as backing to the cover film. However, such methods require two sheets of film, making the sealing structure complicated. Accordingly, there has been proposed a method for tearing the film along an intermittent line of perforations (machine sewing line), but there are problems such as the resulting opening being imprecise in dimensions, and the fine toner particles leaking from the perforations.